The disclosure of Japanese Patent Application No. HEI 11-298733 filed on Oct. 20, 1999 including the specification, drawings and abstract is incorporated herein by reference in its entirety.
1. Field of the Invention
The present invention relates to a hydrogen using system installed in a passenger car or the like.
2. Description of the Related Art
Various low emission vehicles have recently been developed in response to environmental needs. Among the low emission vehicles are electric vehicles using fuel cells as a power source. As well known, hydrogen is normally used as a fuel for fuel cells installed in electric vehicles. A fuel cell is therefore an example of a hydrogen using system, although other systems which use hydrogen and which may be installed in a vehicle, for example a hydrogen combustor, and others, could be envisaged and are incorporated into the definition of a hydrogen using system, as this term is used herein. However, since hydrogen can react with air at predetermined concentrations, for example by combustion or an explosion, it is essential for a vehicle incorporating a hydrogen using system to have provisions for protecting against such a reaction, or for minimizing its effect, in the case where the vehicle is involved in a collision.
An example of a conventional provision is the hydrogen using system for installation in a vehicle described in Japanese Patent Application Laid-Open No. HEI 5-77648. In this hydrogen using system, impact absorbing beams are provided around a fuel cell generator apparatus so as to prevent impact forces occurring et the time of a vehicle crash or the like from reaching the fuel cell generator apparatus. Furthermore, a protective barrier is provided around the hydrogen using system so that if the aforementioned reaction should be induced by a breakage of the fuel cell generator apparatus or the like, the effect of the reaction will be prevented from reaching the occupants.
However, in the aforementioned conventional hydrogen using system for installation in a vehicle, in which the fuel cell generator apparatus is provided with a protective barrier and the vehicle structure is strengthened, the reaction of the hydrogen itself cannot be controlled or stopped although the risk to occupants can be reduced. Therefore, there still is a possibility that the reaction of hydrogen will occur at the time of a vehicle crash or the like.
Accordingly, it is an object of the invention to provide a hydrogen using system for installation in a vehicle that improves its safety by curbing reactions of hydrogen in case of an accident.
To achieve the aforementioned and other objects, a hydrogen using system for installation in a vehicle in accordance with a first aspect of the invention includes a fuel cell portion that provides an electromotive force using hydrogen as a fuel, a conveyance passage that conveys the hydrogen and a source material for producing the hydrogen, and a shutter that shuts the conveyance passage in accordance with an impact on the vehicle.
Due to the above-described construction of the hydrogen using system for installation in a vehicle, when an impact occurs on the vehicle, for example, at the time of a crash or the like, the conveyance passage related to conveyance of the hydrogen or the hydrogen-producing source material is shut in accordance with the impact on the vehicle. Therefore, even in case of such an accident, the amount of hydrogen leaking from the hydrogen using system can be minimized. As a result, the aforementioned reactions of hydrogen can be curbed.
Further, the hydrogen using system may include a first passage that conveys the source material for producing the hydrogen, and a second shutter positioned to shut the first passage, the second shutter being operative to shut the first passage in accordance with an impact on the vehicle.
The hydrogen using system for installation in a vehicle may further include an impact sensor that detects the impact on the vehicle, and the shutter may include a valve that opens and closes the conveyance passage and a controller that forcibly closes the valve based on the detection of the impact by the impact sensor.
Therefore, the hydrogen using system is able to surely detect an impact on the vehicle and, based on the detection, surely shut the passage.
The hydrogen using system for installation in a vehicle in accordance with the first aspect of the invention may further include a tank that stores the source material for producing the hydrogen, and a reformer that produces the hydrogen by reforming the source material. In this case, the source material from the tank is supplied to the reformer via a first passage of the conveyance passage. The hydrogen produced through reforming by the reformer is supplied to the fuel cell portion via a second passage of the conveyance passage. A valve may be provided for each of the first passage and the second passage.
Therefore, if an accident occurs in, for example, a hydrogen using system wherein hydrogen fuel is provided by reforming a hydrogen-producing source material such as methanol or the like, leakage of the hydrogen-producing source material and leakage of hydrogen produced by reforming the source material can be reduced.
The hydrogen using system for installation in a vehicle in accordance with the aspect of the invention may further include a first tank that stores the source material for producing the hydrogen, a reformer that produces the hydrogen by reforming the source material, and a second tank that temporarily stores the hydrogen produced through reforming by the reformer. In this case, the source material from the first tank is supplied to the reformer via a first passage of the conveyance passage. The hydrogen produced by reforming in the reformer is supplied to the second tank via a second passage. The hydrogen from the second tank is supplied to the fuel cell portion via a third passage. The valve may be provided for each of the first passage, the second passage, and the third passage.
Therefore, even a hydrogen using system having a second tank is able to curb the leakage of hydrogen from the second tank and secure safety.
The hydrogen using system for installation in a vehicle in accordance with this aspect of the invention may further include a tank that stores the hydrogen. In this case, the hydrogen from the tank is supplied to the fuel cell portion via the passage. A valve may be provided for the conveyance passage between the tank and the fuel cell portion.
Therefore, if an accident occurs in a hydrogen using system having a tank that stores hydrogen, leakage of hydrogen from the hydrogen storage tank can be suitably curbed.
Furthermore, the hydrogen using system for installation in a vehicle may further include a hydrogen storage tank that stores hydrogen, wherein the hydrogen from the hydrogen storage tank is supplied to the fuel cell portion via a first passage, and any hydrogen that is not consumed in the fuel cell portion is recirculated to the first passage via a second passage. A valve may be provided for each of the first passage and the second passage.
Therefore, even a hydrogen using system having a passage (second passage) for recirculating any hydrogen that is not consumed in the fuel cell portion is able to suitably curb leakage of hydrogen from the hydrogen storage tank and from the fuel cell portion by shutting the circulation passage as well.
A hydrogen using system for installation in a vehicle in accordance with another aspect of the invention includes a hydrogen reaction portion that uses hydrogen as a fuel, a passage that conveys the hydrogen and a source material for producing the hydrogen, and a passage shutter that shuts the passage in accordance with an impact on the vehicle.
In a hydrogen using system for installation in a vehicle having a hydrogen reactor that uses hydrogen as a fuel, such as a hydrogen combustor (e.g., a hydrogen engine) or the like, there is a concern about hydrogen leakage or the like if a crash or the like should occurs, as is the case with the above-described system. Due to the system construction in accordance with this aspect of the invention, if an impact occurs on the vehicle, for example, at the time of a crash or the like, the system having the hydrogen reactor shuts the conveyance passage related to the conveyance of hydrogen or a hydrogen-producing source material in accordance with the impact on the vehicle.
Therefore, in case of an accident, the amount of hydrogen leaking from the hydrogen using system can be minimized, so that the aforementioned reactions of hydrogen can be curbed.
In a control method for a hydrogen using system for installation in a vehicle in accordance with still another aspect of the invention, an impact on the vehicle is detected and, in accordance with the impact on the vehicle, a passage that conveys hydrogen or a materiel for producing the hydrogen is shut. Therefore, if an impact occurs on the vehicle, for example, at the time of a crash or the like, the passage related to the conveyance of hydrogen or the hydrogen-producing source material is shut in accordance with the impact on the vehicle. Hence, in case of such an accident, the amount of hydrogen leaking from the hydrogen using system can be minimized. As a result, the aforementioned reactions of hydrogen can be curbed.